ZF8HP70 for ZF6HP28 swap?

[powershift]

The 8 speed looks pretty good, it has 6th gear as 1:1. It also has a numerically higher first gear so it would feel like a power gain off the line after a swap.

 

[Rover Range]

On the V8s ( 6 and 8 speed) rear diff ratios are the same. 3.54:1
V6 6 speed diff ratio is 3.73:1

 

[djkaosone]

On the V8s ( 6 and 8 speed) rear diff ratios are the same. 3.54:1
V6 6 speed diff ratio is 3.73:1

Interesting... If I have bigger tires, can I simply swap out my 3.54:1 rear diff to a 3.73:1 to fix my acceleration, torque, mpgs, etc? What is the part number for the 3.73:1 rear diff?

 

[powershift]

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[Rover Range]

Interesting... If I have bigger tires, can I simply swap out my 3.54:1 rear diff to a 3.73:1 to fix my acceleration, torque, mpgs, etc? What is the part number for the 3.73:1 rear diff?

I'd have to find out the part #s.
Front diff will need to be changed also.

 

[Tapps33]

Interesting... If I have bigger tires, can I simply swap out my 3.54:1 rear diff to a 3.73:1 to fix my acceleration, torque, mpgs, etc? What is the part number for the 3.73:1 rear diff?

I would argue, given the number of "parts only" cars on marketplace/ebay, you could pick up a set of 3.54 axles pretty cheaply.

And yes, the 3.73 would make a big difference....although, depending on how the math works out, you may lose some top end speed given the differences in the gear ration and tire diameter vs stock V8 6sp trans gears and stock tires....you know, so like 115 instead of 120. LOL!

 

[Tapps33]

The 8 speed looks pretty good, it has 6th gear as 1:1. It also has a numerically higher first gear so it would feel like a power gain off the line after a swap.

That's my general thoughts...I just can't find anyone who's integrated the 8spd into the "legacy" V8's. The first problem alone would be resetting the VIN in the TCM so the truck will let you shift...then there's the whole compatibility issue.

But it would be nice....

 

[f1racer328]

you know, so like 115 instead of 120.

Funny thing is, I think an LR4 will go a bit faster than 120 judging by what I've experienced. Haven't done it though, as this things a brick.

 

[powershift]

For the 2012 model year 4th gear tops out at 121 MPH according to a brochure. 4th gear is a beauty. I can't wait to be on private roads in Mexico to wind it out. It does seem like a plausible claim because it will do 100 MPH easily.

 

[Al Pizzica]

The 6 speed is pretty nice. It has 2 overdrive gears. 4th will go up or down any freeway and then there are two overdrive gears. 5th is a sweet gear for going down 7% grades. I don't need to touch the brakes at all.

Tbh, I wouldn't know what to do with 2 more gears. There might be a point where there is too much shifting. Ford has their 10 speed and it seems like there is a lot of shifting going on. Shifting creates heat and that isn't great for going up a grade unless its winter. I like long gears where you can hold the pedal down and it just pulls uninterrupted for a long time. With today's auto transmissions there would be 4 shifts in that same amount of time of winding out a gear from yesteryear.

I can tell you from direct experience the ZF8 blows away the ZF6. Not even close: blows it away.
It not just about 2 more gears. It just works better and feels better.
Maybe it was BMW mapping. I had 2 X6s with the V8/ZF8 and three LR's with the ZF6: I would die to have the ZF8 behind my 5.0 LR4.
I hope OP takes on this project, as ryanjl said, it has already been done by LR in other vehicles.